For mozilla-mobile#27016 - Prevent the MR onboarding always going to …

…homescreen

This will mean that hen the onboarding is finished the user will get back to
the screen that should've been opened if not the onboarding.

app/src/main/res/navigation/nav_graph.xml

@@ -31,8 +31,7 @@
 
     <action
         android:id="@+id/action_global_home_onboarding_dialog"
-        app:destination="@id/homeOnboardingDialogFragment"
-        app:popUpTo="@id/homeFragment" />
+        app:destination="@id/homeOnboardingDialogFragment" />
 
     <action
         android:id="@+id/action_global_wallpaper_onboarding_dialog"